Apparatus for heating and transfer of articles



May 1, 1928.

H. P. MGCANN APPARATUS FOR HEATING AND TRANSFER OF ARTICLES Filed March17, 1926 lll|u|| llllllllllllllll 4 Sheets-Sheet 1 May 1, 1928,.

v H. P. M CANN APPARATUS FOR HEATING AND TRANSFER 0? ARTICLES FiledMarch 17,- 19 25 4 Sheets-Sheet 2 [ark/liar mum m m .m 1 V "M m m A 1. mm/mw 31K u m EN mw u Q Q Q L w@ a Q R o 7 a V W\ h l Q\ EN N A Q u I 4 um n 0 w U D U U D w h R w 3 S Q A m mu 0 m6 1Q May 1, 1928. 1,668,164

\ H. P. M CANN APPARATUS Fofl ilfefll'wgr OF ARTICLES I 4 Sheets Sheet 3INVENTOR May 1,1928. 4 A 1,668,164 H. P. M cANN APPARATUS FOR HEATINGAND TRANSFER OF ARTICLES.

.Filed March 17, 1926 4 Sheets-Sheet 4 Y 4 r 4 0/ \C) O O *6) r1 j I Q AI a 24 I L I I INVEN1$DR J WWW HARRY r. mcCA PATENT OFFICE.

cw; or REISSUED APPARATUS FOR HEA'FIJING Ann inimises-151 ARTICLES.

Application aka This invention relates to furnaces usedfo'rmetallurgical purposes, and more partit larly to furnaces of the typethat are on? ployed for theheat-treatment of articles and wherein thearticles are conveyed through one or more heat-treating chambers at arate of travel which will permit them to receive the desired ornecessary treatment before being finally removed or dischargedtherefrom.

Among the general objects of the invention, are the provision of afurnace with a quenching tank and with means for delivering thearticles, in a suitable manner and preferably oneat a time, into suchtank; also to provide a furnace of the character described withefiicient means for transferring the articles automatically from thequenching tank to another heat-treatment chamber. Further and morelimited objects of .the invention will be set forth in the specificationand will be accomplished in and through the construction andarra-ngement'of parts shown in the drawings, wherein Fig. 1 represents aside elevation of a furnace embodying my invention, the rear of thefurnace being broken away and the walking beams being in-their loweredor non-feeding position; Fig. 2 a vertical longitudinal section throughsaid furnace, the parts being in the positions which they assume whenthe beams are in elevated feeding position; Fig. 3v a transversesectional view through the rear portion of the furnace shown in Fig. 2;Fig. 4 a detail in plan of the rear part of the furnace, showing themechanism for receiving the articles from the lowerheat-treatmentchamber, and for delivering them to the quenching tank and to theelevating conveyor; Fig. 5 a detail in section of the mechanism shown inFig. 4, the parts being in the positions which they assume prior todelivering an article to the quenching tank; and Fig. 6 a view similarto Fig. 5. showing the positions assumed by the-parts when an article isbeing delivered to the quenching tank.

In the preferredemlmdiment of my invention. I have illustrated somewhatdiagran'imatically a heat-treatment furnace of the tvpe shown in myapplication No. 10,770

filed February 2l,1925, and I have shown the said furnace as providedwith a hearth having a walking-beam arrangement for feeding articlesalong the hearth and tl'irough the heat-treatment chamber above suchhearth in substantially the same manner as shown in my Patent No.1,400,367 issued De- 17, 1926;" seria in; 95,258.

v cember 13, i921. The furnace so illustrated and so equipped isprovided with a quenchmg. tank, a chute for conducting into the tankarticles delivered successively thereto by the intermittent movements ofthe walking beams; there being special means for supporting the articlesin the chute against tilting and for insuring the delivery of the sameinproper relation to conveying means by which the said articles aretransferred from the quenchingtank to another heattreatmentehamberpreferably in the same iurnace and'above thefirst-mentionedchamer. 1 Describing the parts by reference charactcrr, Arepresents a lower heat-treatment chamber, B a combustion chamberthereabove,() a distributing chamber above the chamber B, and D an upperheat-treatment chamber.

The chamber A is provided with a hearth 1 provided with longitudinalslots 2 there through (Fig. 4) in which there are disposed walking-beams3 for moving the work-arti- .cles (shown as round bars 4) step by stepthrough the said chamber. In order to move the articles through thechamber 1 in the manner described, I have provided mechanism similar tothat shown in my patent aforesaid whereby the beams 3 will be elevatedabove the hearth sections 1, thereby lifting the articles from suchsections; will be moved rearwardly the desired distance while in suchelevated position, carrying the articles rearwardly with them, will thenbe lowered, thereby to deposit the articles upon the hearth sections inadvanced position; and will finally be moved,-below the hearth level, toinitial position. The mechanism for effecting this result compriseslevers adapted to raise and lower the said beams, with other mechanismoperating upon the beams, when elevated, to move them rearwardly thedesired'distance and to operate upon the beams, when lowered, to movethem a like distance in the reverse direction. The lifting mechanismwill now be described :-5 denotes a rod extending longitudinally of thefurnace below the central portion thereof, the'sa-id rod being pivotallyconnected at its front end with the lower end of a lever 7 which ispivoted at 8 and which has at its upper end a roller 9 engaging a cam 10on a shaft 11. Arms 12 are pivotally connected at their lower endsto therod 5, as shown at 13, being rigidly connected at their upper ends torock shafts 14 extending transverselyof the bottom of the furnace andeach having rigid therewith a pair of laterally-spaced levers 15, thelevers being located below the beams '3 and each having at its u per enda roller the block and being provided with bloc engaging abutments 23,24 on opposite sides of the block. Several abutments 24 may be employed,the same being removably mounted upon the rod 22, whereby the distancebe tween the front abutment 22 and the particular operatin rear abutment24 may be varied, there y to efiect like variations in the extent 'ofthe lost-motion connection between the link and the block 20 withcorre-'- spondin variations in the periods of rest between t ereciprocations of the walking beams. E denotes a quenching tank at therear of the furnace, there being a chute arranged to receive thearticles as they are delivered from the rear end of the hearth by thewalking beams. As will be seenin Fig. 2, the rear end of thehearthicomprises a transversely extending block 19'. having slots 2 forangular rear extensions'3 'of the walk ing beams. The rear end oftheblock 1 is beveled downwardly and rearwardl and from the bottom of-suchbeveled portion extend the laterally-spaced chute members 25,

the outer chute members being provided each with a side flange 25', theflanges serving as side walls for the chute. Each chute member isprovided with a transversely extending bottom flange 25" the saidflanges constituting a chute bottom adapted to receive an articledelivered to the chute and to hold itin operative relation to thetransverselyalined lifters 26 mounted on cross bars 26" extendingbetween and carried by a pair of conveyor chains 26, the said chainsbeing mounted on lower sprockets 27 carried by a transverse shaft 28.The mounting. of the "upper ends of the chains will be describedhereinafter.

In connection with the mechanism for feeding the articles through thechamber A, I provide take-off mechanism for receiving the articles asthey are delivered over the rear end 1 of the hearth and for maintainingsaid articles transversely of the chute while loweringthem to a positionadjacent t-ht-- lifters 26 before them. This delivers the articles uponthe transverselymoving the walking rovided with an arm 30 which isconnected y a link 31 with a lever 32 which is pivoted at its lower endto a suitable support 33 and is connected intermediate of its ends by alink 34 with the rod 5 which raises and lowers the walking beams. 4

Rigid with the rock shaft 29 is a series of I arms 36, three such armsbein shown and the arms being adapted to wor within the slots providedbetween the chute members 25. When the walking beams are in theirlowered positions, the arms 36 will be thrown downwardl to the positionshown in Fig. 1, with their ends 36' below and in front .of the chute.When the walking beams are in their elevated position, as shown in Fi 2,the rod 5 will have operated the roc shaft 29 to project the ends 36 ofthe arms throu h the slots 25 and to move such ends to t e upper ends ofthe slots, in position to receive the articles delivered from thehearth. The manner in which the work is so delivered will be apparentfrom Figs. 5 and 6. The former figure shows the articles 4 supported bthe hearth sections 1, the rearmost article in adjacent to the rear endof the hearth an the walking beams bein in their lowered and rearwardsition. n Fig. 6, the walking beam is s own in full linesin its elevatedforward position, in which position it lifts all of the pieces of workor articles 4 except the rearmost article, which is supported upon thehearth sections 1. When thewalking beams are moved rearwardly totheposition shown in dotted lines, the rearmost piece of work is movedthereby beyond the rear edge of the hearth and drops down the chute, asshown in dotted lines at 4", in position to be received by the arms 36except for the action of the blocking mechanism which is employed toprevent a premature. or accidental delivery of an article in the chuteand into the quenching tank- This blocking mechanism com )rise's anL-shaped frame, indicated genera ly at.

37 and having at its front end the obstructing flanges 37 the front ofthe frame being adapted to rest upon the rear of the hearth section 1'(see Fig. 5). This frame 37 is provided with trunnions 38 mounted injournals 39 in the sids of the furnace, being overweighted forwardly sothat it tends to rest with its front edge upon the rear of the hearth.In the bottom of the frame 37 are mounted rollers 40, these rollersregistering with th slots between the chute mem.

bers The parts are so arranged that,

when the beams 3 are elevated, the motion of the rod 5 will rock theshaft 29 to throw the arms 36 upwardly, the upper ends 36 of these arms,engaging the rollers 40, tilt the fran1c 37 to the position shown inFig. 6, thereby providing a space below the front of said frame for thepassage of a piece of work 4 over the rear end of the hearth. ()n therearward movement of the walking beams, this piece of work is moved overthe rear end of the hearth by the walking-beam extensions 3 and dropsdown into the pocket formed between the bottom of the frame 37 and thebeveled rear wall of the hearth. Through the lowering movement of thewalking beams, the arms 36 are lowered, therebydisengaging the rollers40, receiving the article 4 and lowering the same nearly to the bottomof the chute, when the arms pass through the slots between the chutemembers and deliver the article upon the transversely-alined lifters 26.

The upper ends of the conveyor chains 26 pass around idle sprockets 41so located as to cause the lifters 26 to deliver the articles carriedthereby upon the side chains 42 of a conveyor, the same traveling ontracks 43 within the chamber D. The chains 42 are supported at theirrear ends on idle pinions 44 which may be conveniently mounted looselyupon the shaft 45 which carries the idle sprockets 41. The chains 26pass over sprockets 46 mounted on a shaft 47 and thence around idlesprockets 48 and back to the sprockets 27. The lever 7 is looselymounted on the shaft 8, which is the drive shaft for the conveyors. Onone end of the shaft is a sprocket 49. A chain 50 passes around thissprocket and around a sprocket on the shaft 51, thereby driving saidshaft and a sprocket 52 thereon. A chain 53 passing around the lastmentioned sprocket drives a'sprocket 54 at the rear of the furnace. Onthe shaft 55 of the last mentioned sprocket is a gear (not shown) whichmeshes with a gear, (not shown) on the shaft 47, thereby to drive thesaid sprocket and the conveyor chains 26 ,in the appropriate direction.A sprocket (not shown) on the shaft 51 and a chain 56 extending aroundsuch sprocket and around a sprocket 57' drive a shaft 58. This shaftsupports the front sprockets 59 about which the conveyor chains 42extend.

In the furnace shown herein, the combustion chamber-B will be providedwith suitable burners (not shown), the arch B beneath the said chamberbeing provided with perforations B which will permit access of heat andproducts of combustion to the chamber A. From the bottom of the chamberA, a flue 60 delivers the products of combustion to the intermediatechamber C. This chamber is heated by the products of combustion as wellas by thearch B above the chamber B. The products of combustion in thechamber C heat the wall 61 between the chambers C and D, while theproducts from the chamber C are delivered into the chamber D throughlines 62, whence they are discharged through flues 63. One of the burnerinlets is indicated at 64.

With the parts constructed and arranged as described the operation willbe briefly as follows:-'l'he articles 4 are conducted through thechamber A, step by step, by

the movements of the walking beams 3 described hereinbefore, thesemovements being effected by the cam 10, lever 7, rod 5, arms 12, arms15, and by the crank 21, rod 22, and the abutments 22, 24, arms 19, andblock 23. During each reciprocation of the rod 5, the arms 30 are movedupwardly to rock the frame 37 rearwardly thereby to receive the articledelivered from the rear end of the health by the rearward movement ofthe elevated walking beams. The movement of the rod 5 in the reversedirection lowers the arms 36', carrying the article 4 with them to nearthe bottom of the chute 25, where it is delivered to"transversely'alined lifters 26 on the conveyor chains 26 and deliveredonto the conveyor other chamber, the said conveyorhaving series oflaterally spaced artlcle-supporting members, and movable meanscooperating with the chute for receiving articles delivered successivelythereto from the first chamber and for delivering them in properoperative relation to the said members.

2. In an apparatus of the character described, the combination of afirst and a second heat-treatmentchamber and means for heating the same,of a quenching tank inter posed between said chambers and located belowthe first chamber, means for moving articles progressively through thefirst chamber and delivering the same to said tank, a

conveyor in the second chamber, a conveyor having laterally spacedseries of article-supporting members and arranged to deliver articlesfrom said tank to'the other conveyor, and movable means cooperatingsuccessively with the articles chamber for delivering them in properreladelivered from the first through the delivery of articles to theupper end of said chute for moving the said arms upwardly in position toreceive an article delivered to such portion of the chute and. .formoving the said arms downwardly to convey an article received thereby tothe lower poi tion of saidchute, and a conveyor arranged below said armsand having a series of laterally-spaced lifting members arran ed toreceive the articles conveyed by sai arms, the said conveyor exten ingin operative relation to the other heat-treatment chamber.

4. In an apparatus of the character described, the combination of alower and an upper heat-treatment chamber, a quenching tank below thesaid chambers a chute interposed between the delivery end of one of saidchambers and the tank, means for feeding articles rogressivel throu hthe last-men- I tioned c amber an for de ivering them to in one or morevertically arranged thcup r portion of said chute, a series of lateral yspaced arms arranged to 0 rate ots in said chute thereby to receivearticles delivered to the upper and means operative y thearticle-feeding means for movin the said arms in position to receive thearticles delivered to such portion of the chute and for moving the saidarms downwardly in said slot or slots, and

a conveyor arranged below said arms and having a series oflaterally-spaced members arranged toreoeive the articles from said arms,the said conveyor extending in operative relation to the other heat-treeV ment chamber.

5. An apparatus for the heat-treatment of articles comprising a lowerheatetreatment chamber and an up her and means for tingthe same, meansfor conveying articles ro ively through.

the first-mentioned c am r, a quenching tank below the delivery end ofthe firstmentioned chamber, a conveyor extending from said quenchingtank to the upper chamber, the said conveyor having series of laterallyspaced lifting members, a chute for receiving articles from the deliv'endof the first mentioned chamber and hvering I them into the said tank,in operative relation to said lifting members, article-receiving isadapted to receive tromthe rtionof said chute,

r heat-treatment cham-v delivery end of the first-mentioned chamber andsupport and conduct them along said chute and deliver them to theappropriate lifting members, and means controlled by the feeding of thearticles through the first mentioned chamber for operating the saidarms.

6. An apparatus for the heat treatment of articles com rising a lowerheat-treatment chamber and an upper heat-treatment chamber and means foreating the same, means for conveyin'g'articles progressively through thefirst-mentioned chamber a quenching tank below the delivery end 0 thefirst mentioned from said chamber, a conveyor exten quenching tank tothe upper camber, the said conveyor having series of laterally spacedlifting members, a chute for receiving articles from the delivery end ofthe first mentioned chamber and delivering them into the said tank inoperative relation to said lifting members, adapted to receive articlesfrom the delivery end of the first-mentioned chamber and support andconduct them along said chute and deliver them to the appropriate liftinmembers, and means for operating the sai arms. 7. In an apparatus of thecharacter described, the combination of a lower heattreatment chamber,an up r heat-treatment chamber, a quenching below the lower chamber, ahearth in the lower chamber, oneor more beams each operable through aslot in said hearth, means for raising and lowerand reciprocating thesaid beam or beams w ereby articles to be heated in the first chambermay be conducted step by step thl'OltlEh the said chamber to thedelivery end ereof, a vertically-slotted chute at the delivery end ofthe hearth and leading to said tank, a conveyor extending from said tankin operative relation to the upper chamber, the said conveyor havinglaterallyspaced series of liftin members arranged to pass through theslots in the said chute, arms pivotally supported adjacent the rear ofthe said furnace and am to be moved u .wardly and downwardly in theslots of t e chamber, ahearth in the lower chamber, one.

or more beams-each operable through a slot in said hearth, means forraising and lowering and reciprocating'the said beam or beams w e rebyarticles to be heated in the first chamber may I be conductedstep-bythrough the said chamber to the delivery and article-receivingarms heat- Ill thereof, a chute at the delive end of the hearth andleading to said tan a conveyor extending from sa1d tank in operativerelathrough said chamber,

tion to the upper chamber, the said conveyor having laterally-spacedseries of lifting members, arms pivotally supported adjacent the rear ofthe said furnace and arranged to be moved upwardly and downwardlythereby to receive the articles as they are delivered, successively fromthe said hearth and to support theminproper position for delivery to thelifting members and means for operating the said arms.

9. In a furnace having a heat-treatment chamber and means for feedingarticles successivel through said chamber; to the delivery en thereof, aquenching tank, a vertically slotted chute extending from the deliveryend of said chamber to said tank, arms pivoted so that their ends may bemoved through the said slots and upwardly into article-receivingposition and downwardly into delivering position adjacent the lower endof said chute, a conveyor, having laterall spaced series of liftingmembers operab e throu h said slots and adapted to receive articlisidropped from the ends of said arms, and means controlled by the feed ofthe articles through the said chamber for operating the said arms.

-10. Ina furnace having a heat-treatment chamber with a hearth and meansfor moving articles to ,be heat-treated. progressively atransversely-arrange series of arms adapted'to receive articlesdelivered by said moving means from the rear-end of said hearth and -todeliver the same to a conveyor, means operated 'by such article-movingmeans for moving the arms into receiving position when the beams aremoved rearwar'dly and for lowering the a said arms into deliveryposition when the beams are moved forwardly, and means normallyblocking. the delivery of articles from said hearth, the last mentionedmeans being adapted to be moved out of blocking relation to said hearthwhen the arms are in articlereceiving position. v

11. In a furnace having a heat treatment chamber with a hearth and oneor more beams for moving articles to be heat treated successivelythrough said chamber, movable means adapted to receivecarticlesdelivered by said beams from the rear end of said hearthand to deliverthe same to a conveyor,- means for moving the last-mentioned means intoreceivingk position when the beams'are move'd rearwardlyand for loweringthe same into delivery position when the beams are i -to said hearthwhenthe receiving and delivering means are in article-receiving position.

of articles, the combinationof a chamber having a hearth, one or 'morebeamsfor feeding articles progressively through said chamber, the saidbeams being movable to positions above and below said hearth, with meansfor moving the beams rearwardly when in elevated position and forwardlywhen in depressed position, there being a delivery chute at the rear endof said hearth and ,the said beams being arranged, when in their upperand rearward position, to deliver the rearmost articles to said chute,an L-shapcd member pivoted adjacent the rear end of said hearth with itsupper end nor mally blocking the delivery of an article therefrom tosaid chute, and laterally spaced arms movable into article-receiving andarticle-delivering position, one of said arms being arranged to engagethe said blocking member as said arms are moved into receiving position,thereby to operate the blocking member and to permit the articles to bedelivered from the hearth to the said arms.

13. In a furnace for the heat-treatn'ient of articles the combination ofa chamber, meansfor feeding articles progressively through said chamber,an L-sha'ped member pivoted adjacent the rear end of said hearth withits upper end normally blocking the delivery of an article therefrom,means movable 'into article-receiving and article-delivering position,the said means being arrangedto engage the said blocking member whenmoved into receiving position, thereby to operate the blocking memberand to permit the arti les to be delivered from the hearth to he saidreceiving and deliverin' means.

14, 11 an apparatus of the'character dcscribed,-the combination, with. afirst and a second heat-treatment chamber and means said hearth and thesaid tank, means for feeding articles to be heated progressively throughthe first of said chambers and for delivering the same to said chute, aconveyor extending from-the quenching tank in operative relation to thesecond chamber, the said conveyor having series of laterally-. spacedlifting members, and receiving means, operable by the movement of thesaid feeding means, for receiving the articles successively as they are.delivered 'from the hearth and delivering them to the lower portion ofthe chute and in roper operative relation to the lifting me be conveyor.

15. A furnace com-prising a heat-treatment chamber having a slottedhearth, one

rson the said means or more beams each operable in a slot of the ingposition, and connections between the hearth, means for moving the saidbeam or beams vertically, and longitudinally relative to said hearthwherebyv the said beam or beams are projected above the hearth to liftthe articles thereupon, are moved rearwardly, are lowered to deposit thearticles in advanced position upon the hearth, and are moved rearwardlyto initial position, the rear ends of the beams being so located as todislodge from the delivery end'of the hearth the rearmost articlethereon by the move ment of the said beams rearwardly, an L- shapedmember pivotally su ported at the rear of the delivery end of the hearthwith its front portion adapted to block the delivery of the rearmostarticle from said hearth, anda work-receiving arm'movable toward andfrom the delivery end of the hearth and adapted to engage the saidmember when moved to work-receiving osition thereby to rock, the memberaway m ts work obstructin position and permit the article to'be deivered from the hearth by the movement of said beam'or beams.

16. A furnace comprisin a heat-treatprogressively through said chamber,an L- shaped member pivotally supported at the rear of the delivery endof the chamber with its front ortion adapted to block the de livery of tie rearmost article therefrom, and a work-receivin member movable towardand from the d ivery end of the hearth and adapted to-rengage the saidblocking member when moved to work-receiving position,

thereby'to rock the latter member away from its work-obstructing itionand rmit the article to be delivere from said 0 amber.

17. A furnace comprisin a heat-treatment chamber havin a slot-te hearth,one or more beams eac operable in a slot of the hearth, meansv formoving the said beam or beams vertically and longitudinally relative tosaid hearth whereby the said beam or beams are projected above thehearth to lift the articles thereupon, are moved rearwardly, are loweredto deposit the articles in advanced position upon the hearth, and aremoved rearwardly to initial position, the rear ends of the beams beingso located as to dislodge from the delivery end of the hearth therearmost article thereon by the movement of the said beams-rearwardly,an L- sha d member pivoted adjacent to the rear f ti hearth and adaptedto swing by avity about its pivotal sup rt thereby to lock with itsfront end the (l livery of an article from the rear end of said hearth,rollers on the lower end of said member, receiving arms movable towardand from the delivery end of the hearth and each arranged, when moved.

to receiving position, to en a e a roller on said member thereby to roct e member to move its front portion out of work-obstructsaid arms andthe said beams for raising the same to work-receiving position in timeto receive the article dislodged by the rearward movement of the beam orbeams and to lower the arms to delivering position before the nextrearward movement of the beam or beams.

g 18. A furnace comprising a heat-treatment chamber, means forfeedingkarticles progressively through said cham r, an L-shaped mem erpivoted adjacent to the rear of the chamber and adapted to swing bygravity about its pivotal support thereby to block with its front endthe delivery of an article from the rear end of said chamber, receivingmeans movable toward and from the delivery end of the chamber andarranged when moved to receivin .position said member there y to rocirthe same and move its front portion out ofwork-obstructing position, andconnections between the said receivin means and the feeding means formoving e former means to work-receivmg position in time to receive anarticle der. 19. A heat-treatment furnace comprising an intermediatecombustion chamber, a heattreatment chamber below said combustionchamber and a heat-treatment chamber above said combustion chamber, aconveyor in the upper chamber, means for feeding ar- 4 ticlessuccessively thro the first-mentioned chamber, a quen tank beneath thefirst-mentioned chamber, a conveyor to engage the livered by the feedingmeans from the chamment chamber, means for coding art cles be 4 forconducting articles from saidtank to the first mentioned conveyor andmeans for delivering articles from c first mentioned chamber to the tankand to the second conveyor.

20. In a furnace having a chamber for the heat treatment of articlesand. a quenching tank below the delivery end of said chamber means forfeeding the articles to be treated progressively through said chamber,movable means adapted to receive the articles delivered from saidchamber and to lower the same into said tank, and means controlled bythe article-feeding means.

21. In a furnace having a chamberfor' the heat treatment of articles anda quenching tank below the delivery end of said chamber means foroperating said means for feeding the. articles to be treatedprogressively through said chamber, arms adapted to receive the articlesdelivered from sal chamber and to lower the same into said tank, andmeans controlled fe'edm means for operating and arms.

' 22. u an apparatus of the character deby the article- III scribed, thecombination, with a lower heats treatment chamber, an upperheat-treatment chamber, and a combustion chamber between the saidheatstreatment chambers, of

- for feeding articles pro essively throu h the first heat-treatment ciamber, a uenc ing tank below the delivery end of t e firstheat-treatment chamber, a conveyor having its lower end in said tank andits u per end arranged in operative relation to tie upper heat-treatmentchamber, and means for delivering articles successively from the firstheat-treatment chamber into the quenching tank and on the portion of theconveyor therein. a

23. In an apparatus of the character described, the combination, with alower'heattreatment chamber, an upper heat-treatment chamber, and acombustion chamber between the said heat-treatment chambers, of meansfor feeding articles proiressively through the first heat-treatment camber, a uenching tank below the delivery end of t 1e first.

heat-treatment chamber, a conveyor having its lower end in said tank andits upper end arranged in operative relation to the upper heat-treatmentchamber, the said conveyor being provided with article-supportingmembers, and means for delivering to the quenchingitank and to themembers on said conveyor articles discharged from the firstheattreatment chamber. f

In testimony whereof, I hereunto aflix my signature.

"HARRY P. Mac ANN.

